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Planar (r.m.s. deviation from the plane through all non-H atoms = 0.036 Å) mol­ecules of the title compound, C16H11BrO2, form a layered structure stabilized by C—H...O hydrogen bonds and π–π stacking inter­actions.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536810010718/ds2025sup1.cif
Contains datablocks global, I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S1600536810010718/ds2025Isup2.hkl
Contains datablock I

CCDC reference: 774375

Key indicators

  • Single-crystal X-ray study
  • T = 100 K
  • Mean [sigma](C-C) = 0.002 Å
  • R factor = 0.028
  • wR factor = 0.070
  • Data-to-parameter ratio = 34.7

checkCIF/PLATON results

No syntax errors found



Alert level C PLAT910_ALERT_3_C Missing # of FCF Reflections Below Th(Min) ..... 1 PLAT912_ALERT_4_C Missing # of FCF Reflections Above STh/L= 0.600 67
Alert level G PLAT380_ALERT_4_G Check Incorrectly? Oriented X(sp2)-Methyl Moiety C17
0 ALERT level A = In general: serious problem 0 ALERT level B = Potentially serious problem 2 ALERT level C = Check and explain 1 ALERT level G = General alerts; check 0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 0 ALERT type 2 Indicator that the structure model may be wrong or deficient 1 ALERT type 3 Indicator that the structure quality may be low 2 ALERT type 4 Improvement, methodology, query or suggestion 0 ALERT type 5 Informative message, check

Comment top

Seeds, fruit skin, bark and flowers of most plants contain significant amount of flavonoids. They have been classified to one subclass of flavonoids according to their chemical structures (Hsiao et al., 2007). Several naturally occurring and synthetic flavones are well know in respect to their anti-oxidant, anti-neoplastic, anti-malarial, anti-inflammatory and insecticidal activity (Manthey et al., 2001; Millot et al., 2009; Moulari et al., 2006). Halogenoflavones have been used as precursors for the synthesis of a variety of bioactive organic compounds including biflavodoids (Ren et al., 2003; Moon et al., 2007). The title compound is a flavone derivative with 4'-bromo and 6-methyl substituents in the biologically active region (Scheme) (Middleton et al., 2000).

Crystal structures of the following related flavones were reported: 7-hydroxyflavone monohydrate (Kumar et al., 1998), 6-(3-hydroxy-3-methylbut-1-ynyl)-flavone and 6-(3-methylbut-3-en-1-ynyl)-flavone (Artali et al., 2003), 2-phenyl-6-hydroxy-4H-1-benzopyran-4-one (6-hydroxyflavone) (Białońska et al., 2007), 3,5,4'-trihydroxy-6,7-dimethoxy-flavone (Eupalitin) (Ghalib et al., 2010).

Structure of 2-(4-bromophenyl)-6-methyl-4H-1-benzopyran-4-one with the numbering scheme employed is presented in Fig. 1 Molecules of the titled compound form ribbons stabilized by ππ stacking interactions exteded along the [010] direction (Table 2). The neighboring ribbons are linked by C—H···O hydrogen bonds, in which the carbonyl O4 atom is their acceptor (Table 1). The resulting layers perpendicular to the [100] direction (Fig. 2).

Related literature top

For background information on flavones and their properties, see: Hsiao et al. (2007); Manthey et al. (2001); Middleton et al. (2000). Millot et al. (2009); Moulari et al. (2006); Ren et al. (2003); Moon et al. (2007). For related structures, see: Kumar et al. (1998); Artali et al. (2003); Białońska et al. (2007); Ghalib et al. (2010).

Experimental top

The title compound was obtained according to the procedure: A mixture of the para-cresol 1,08 g (10,0 mmol) and 3,4'-dibromopropiophenone 0,59 g (2,0 mmol) in BF3.OEt2 (20 ml) was heated at 60 °C and stirred for 8 h. The products of reaction were extracted from the mixtures with chloroform. Titled product was separated by column chromatography on silica gel with hexane/methyl chloride/acetone (10:1:1 v/v/v) as eluent (Scheme). Crystals suitable for X-ray structure analysis were obtained by slow evaporation from the eluent at room temperature. Structure of the titled product was confirmed by means of the 1H NMR and 13 C NMR spectra. 1H NMR (600 MHz, CDCl3 δ, p.p.m.): 6.81 (s, 1H, H3), 7.48 (d, 1H, J=8.56 Hz, H8), 7.54 (dd, 1H, J=8.56, 2.12 Hz, H7), 7.68 (m, 2H Wh=8.60 Hz, H5' and H7'), 7.80 (m, 2H, Wh=8.60 Hz, H2' and H6'), 8.04 (d, 1H, J=2.12 Hz, H-5). 13 C NMR (150 MHz, CDCl3 δ, p.p.m.): 20.98 (-CH3); 107.55 (C3); 117.83 (C8); 123.56 (C10); 125.13 (C5); 126.25 (C6); 127.71 (C3' i C5'); 130.84 (C1'); 132.35 (C2' i C6'); 135.21 (C7); 135.47 (C4'); 154.48 (C9) 162.23 (C2); 178.48 (C4).

Refinement top

Non-hydrogen atoms were refined with anisotropic displacement parameters. All H atoms were placed at calculated positions and were treated as riding atoms, with C—H distances of 0.95 - 1.00 Å.

Computing details top

Data collection: CrysAlis CCD (Oxford Diffraction, 2009); cell refinement: CrysAlis RED (Oxford Diffraction, 2009); data reduction: CrysAlis RED (Oxford Diffraction, 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP (Bruker, 1999); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. Selected view of 4'-bromo-6-methyloflavone with the numbering scheme employed.
[Figure 2] Fig. 2. Molecular packing of 4'-bromo-6-methyloflavone.
2-(4-Bromophenyl)-6-methyl-4H-1-benzopyran-4-one top
Crystal data top
C16H11BrO2F(000) = 632
Mr = 315.16Dx = 1.645 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 11464 reflections
a = 13.759 (3) Åθ = 3.0–36.9°
b = 6.873 (2) ŵ = 3.22 mm1
c = 13.460 (2) ÅT = 100 K
β = 90.25 (3)°Plate, colorless
V = 1272.8 (5) Å30.31 × 0.29 × 0.04 mm
Z = 4
Data collection top
Kuma KM-4-CCD
diffractometer
5962 independent reflections
Radiation source: fine-focus sealed tube3659 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.047
ω scanθmax = 36.0°, θmin = 3.0°
Absorption correction: analytical
[CrysAlis RED (Oxford Diffraction, 2009); analytical numeric absorption correction using a multifaceted crystal model based on expressions derived by Clark & Reid (1995)]
h = 2222
Tmin = 0.474, Tmax = 0.893k = 1110
25822 measured reflectionsl = 2122
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.028Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.070H-atom parameters constrained
S = 0.88 w = 1/[σ2(Fo2) + (0.0385P)2]
where P = (Fo2 + 2Fc2)/3
5962 reflections(Δ/σ)max < 0.001
172 parametersΔρmax = 0.69 e Å3
0 restraintsΔρmin = 0.37 e Å3
Crystal data top
C16H11BrO2V = 1272.8 (5) Å3
Mr = 315.16Z = 4
Monoclinic, P21/cMo Kα radiation
a = 13.759 (3) ŵ = 3.22 mm1
b = 6.873 (2) ÅT = 100 K
c = 13.460 (2) Å0.31 × 0.29 × 0.04 mm
β = 90.25 (3)°
Data collection top
Kuma KM-4-CCD
diffractometer
5962 independent reflections
Absorption correction: analytical
[CrysAlis RED (Oxford Diffraction, 2009); analytical numeric absorption correction using a multifaceted crystal model based on expressions derived by Clark & Reid (1995)]
3659 reflections with I > 2σ(I)
Tmin = 0.474, Tmax = 0.893Rint = 0.047
25822 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0280 restraints
wR(F2) = 0.070H-atom parameters constrained
S = 0.88Δρmax = 0.69 e Å3
5962 reflectionsΔρmin = 0.37 e Å3
172 parameters
Special details top

Experimental. CrysAlis RED, Oxford Diffraction Ltd., Version 1.171.33.42 (release 29-05-2009 CrysAlis171 .NET) (compiled May 29 2009,17:40:42) Analytical numeric absorption correction using a multifaceted crystal model based on expressions derived by R.C. Clark & J.S. Reid. (Clark, R. C. & Reid, J. S. (1995). Acta Cryst. A51, 887-897)

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Br0.122301 (8)0.12666 (2)0.048602 (10)0.02299 (4)
O10.59232 (6)0.12638 (15)0.20324 (6)0.01526 (15)
C20.51619 (8)0.12091 (19)0.26748 (8)0.01346 (19)
C30.52887 (8)0.1170 (2)0.36736 (8)0.0158 (2)
H3A0.47330.11380.40890.019*
O40.63780 (7)0.11445 (16)0.50391 (6)0.02132 (18)
C40.62442 (8)0.1176 (2)0.41278 (9)0.0152 (2)
C50.80289 (8)0.1197 (2)0.37337 (9)0.0158 (2)
H5A0.81730.11600.44240.019*
C60.87838 (8)0.1235 (2)0.30587 (9)0.0173 (2)
C70.85504 (9)0.1311 (2)0.20364 (9)0.0188 (2)
H7A0.90620.13480.15650.023*
C80.76018 (9)0.1335 (2)0.17014 (9)0.0179 (2)
H8A0.74590.13960.10110.021*
C90.70523 (8)0.1212 (2)0.34182 (8)0.01366 (19)
C100.68548 (8)0.1267 (2)0.24016 (9)0.01469 (19)
C110.42181 (8)0.12034 (19)0.21497 (8)0.01378 (19)
C120.41819 (9)0.1370 (2)0.11092 (9)0.0170 (2)
H12A0.47680.14770.07430.020*
C130.32929 (9)0.1380 (2)0.06124 (9)0.0181 (2)
H13A0.32690.14860.00910.022*
C140.24418 (8)0.1234 (2)0.11563 (9)0.0169 (2)
C150.24576 (9)0.1070 (2)0.21903 (10)0.0184 (2)
H15A0.18690.09800.25530.022*
C160.33448 (9)0.1041 (2)0.26785 (9)0.0166 (2)
H16A0.33630.09100.33810.020*
C170.98418 (9)0.1213 (2)0.33957 (10)0.0217 (2)
H17A0.98710.11600.41230.033*
H17B1.01670.23960.31630.033*
H17C1.01680.00690.31180.033*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Br0.01513 (6)0.02745 (7)0.02633 (7)0.00270 (6)0.00771 (4)0.00266 (6)
O10.0108 (3)0.0227 (4)0.0123 (3)0.0008 (4)0.0008 (3)0.0003 (4)
C20.0130 (4)0.0128 (5)0.0145 (5)0.0002 (5)0.0009 (4)0.0007 (5)
C30.0135 (4)0.0200 (5)0.0139 (5)0.0007 (5)0.0013 (4)0.0001 (5)
O40.0200 (4)0.0308 (5)0.0132 (4)0.0045 (4)0.0010 (3)0.0008 (4)
C40.0155 (5)0.0155 (5)0.0145 (5)0.0015 (5)0.0006 (4)0.0003 (5)
C50.0146 (5)0.0159 (5)0.0169 (5)0.0008 (5)0.0031 (4)0.0006 (5)
C60.0128 (4)0.0177 (5)0.0215 (5)0.0009 (5)0.0020 (4)0.0009 (5)
C70.0137 (5)0.0232 (6)0.0195 (5)0.0004 (5)0.0019 (4)0.0014 (6)
C80.0147 (5)0.0239 (6)0.0150 (5)0.0004 (5)0.0004 (4)0.0012 (5)
C90.0124 (4)0.0143 (5)0.0144 (5)0.0010 (5)0.0005 (4)0.0002 (5)
C100.0115 (4)0.0157 (5)0.0168 (5)0.0008 (5)0.0012 (4)0.0007 (5)
C110.0122 (4)0.0138 (5)0.0154 (5)0.0001 (5)0.0015 (4)0.0002 (5)
C120.0149 (5)0.0191 (6)0.0171 (5)0.0007 (5)0.0005 (4)0.0017 (5)
C130.0178 (5)0.0195 (6)0.0170 (5)0.0008 (5)0.0031 (4)0.0008 (5)
C140.0144 (5)0.0160 (5)0.0203 (5)0.0017 (5)0.0046 (4)0.0008 (5)
C150.0139 (5)0.0196 (6)0.0216 (6)0.0003 (5)0.0001 (4)0.0012 (5)
C160.0138 (5)0.0198 (6)0.0163 (5)0.0001 (5)0.0000 (4)0.0002 (5)
C170.0140 (5)0.0270 (6)0.0240 (6)0.0002 (6)0.0036 (4)0.0022 (6)
Geometric parameters (Å, º) top
Br—C141.9008 (13)C8—C101.3983 (16)
O1—C21.3617 (14)C8—H8A0.9500
O1—C101.3727 (14)C9—C101.3944 (16)
C2—C31.3551 (16)C11—C161.4036 (17)
C2—C111.4757 (16)C11—C121.4059 (16)
C3—C41.4475 (17)C12—C131.3914 (17)
C3—H3A0.9500C12—H12A0.9500
O4—C41.2397 (15)C13—C141.3875 (17)
C4—C91.4692 (16)C13—H13A0.9500
C5—C61.3832 (17)C14—C151.3964 (18)
C5—C91.4075 (16)C15—C161.3839 (17)
C5—H5A0.9500C15—H15A0.9500
C6—C71.4126 (18)C16—H16A0.9500
C6—C171.5228 (17)C17—H17A0.9800
C7—C81.3792 (17)C17—H17B0.9800
C7—H7A0.9500C17—H17C0.9800
C2—O1—C10119.33 (9)O1—C10—C8116.36 (10)
C3—C2—O1122.30 (10)C9—C10—C8121.44 (10)
C3—C2—C11125.75 (11)C16—C11—C12119.01 (11)
O1—C2—C11111.95 (9)C16—C11—C2120.72 (10)
C2—C3—C4122.12 (11)C12—C11—C2120.27 (10)
C2—C3—H3A118.9C13—C12—C11120.42 (11)
C4—C3—H3A118.9C13—C12—H12A119.8
O4—C4—C3123.27 (11)C11—C12—H12A119.8
O4—C4—C9122.28 (11)C14—C13—C12119.23 (11)
C3—C4—C9114.45 (10)C14—C13—H13A120.4
C6—C5—C9121.35 (11)C12—C13—H13A120.4
C6—C5—H5A119.3C13—C14—C15121.48 (11)
C9—C5—H5A119.3C13—C14—Br119.58 (9)
C5—C6—C7118.19 (11)C15—C14—Br118.94 (9)
C5—C6—C17121.59 (11)C16—C15—C14118.97 (12)
C7—C6—C17120.23 (11)C16—C15—H15A120.5
C8—C7—C6121.99 (11)C14—C15—H15A120.5
C8—C7—H7A119.0C15—C16—C11120.88 (12)
C6—C7—H7A119.0C15—C16—H16A119.6
C7—C8—C10118.46 (11)C11—C16—H16A119.6
C7—C8—H8A120.8C6—C17—H17A109.5
C10—C8—H8A120.8C6—C17—H17B109.5
C10—C9—C5118.56 (10)H17A—C17—H17B109.5
C10—C9—C4119.58 (10)C6—C17—H17C109.5
C5—C9—C4121.87 (10)H17A—C17—H17C109.5
O1—C10—C9122.20 (10)H17B—C17—H17C109.5
C10—O1—C2—C30.45 (19)C4—C9—C10—O10.9 (2)
C10—O1—C2—C11179.69 (13)C5—C9—C10—C80.9 (2)
O1—C2—C3—C40.3 (2)C4—C9—C10—C8178.91 (13)
C11—C2—C3—C4179.90 (13)C7—C8—C10—O1179.04 (14)
C2—C3—C4—O4179.89 (13)C7—C8—C10—C91.2 (2)
C2—C3—C4—C90.5 (2)C3—C2—C11—C163.7 (2)
C9—C5—C6—C70.7 (2)O1—C2—C11—C16176.44 (12)
C9—C5—C6—C17179.82 (14)C3—C2—C11—C12175.99 (13)
C5—C6—C7—C80.4 (2)O1—C2—C11—C123.86 (18)
C17—C6—C7—C8179.95 (14)C16—C11—C12—C130.2 (2)
C6—C7—C8—C100.5 (2)C2—C11—C12—C13179.51 (13)
C6—C5—C9—C100.0 (2)C11—C12—C13—C140.3 (2)
C6—C5—C9—C4179.84 (13)C12—C13—C14—C150.2 (2)
O4—C4—C9—C10179.34 (13)C12—C13—C14—Br179.51 (11)
C3—C4—C9—C101.0 (2)C13—C14—C15—C160.4 (2)
O4—C4—C9—C50.5 (2)Br—C14—C15—C16179.84 (11)
C3—C4—C9—C5179.17 (13)C14—C15—C16—C111.0 (2)
C2—O1—C10—C90.1 (2)C12—C11—C16—C150.8 (2)
C2—O1—C10—C8179.67 (12)C2—C11—C16—C15178.85 (14)
C5—C9—C10—O1179.28 (13)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C3—H3A···O4i0.952.493.2904 (17)142
C16—H16A···O4i0.952.583.4394 (16)151
Symmetry code: (i) x+1, y, z+1.

Experimental details

Crystal data
Chemical formulaC16H11BrO2
Mr315.16
Crystal system, space groupMonoclinic, P21/c
Temperature (K)100
a, b, c (Å)13.759 (3), 6.873 (2), 13.460 (2)
β (°) 90.25 (3)
V3)1272.8 (5)
Z4
Radiation typeMo Kα
µ (mm1)3.22
Crystal size (mm)0.31 × 0.29 × 0.04
Data collection
DiffractometerKuma KM-4-CCD
diffractometer
Absorption correctionAnalytical
[CrysAlis RED (Oxford Diffraction, 2009); analytical numeric absorption correction using a multifaceted crystal model based on expressions derived by Clark & Reid (1995)]
Tmin, Tmax0.474, 0.893
No. of measured, independent and
observed [I > 2σ(I)] reflections
25822, 5962, 3659
Rint0.047
(sin θ/λ)max1)0.827
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.028, 0.070, 0.88
No. of reflections5962
No. of parameters172
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.69, 0.37

Computer programs: CrysAlis CCD (Oxford Diffraction, 2009), CrysAlis RED (Oxford Diffraction, 2009), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), XP (Bruker, 1999).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C3—H3A···O4i0.952.493.2904 (17)142.2
C16—H16A···O4i0.952.583.4394 (16)151.2
Symmetry code: (i) x+1, y, z+1.
ππ interactions (Å, °). top
Cg(1) and Cg(2) are the centroids of the C5–C10 and C11–C16 rings, respectively.
Cg(I)Cg(J)CgCgAlphaCgI_perpCgJ_PerpSlippage
Cg(1)Cg(2)i3.8957.13 (3)3.579 (2)-3.430 (2)1.84
Cg(1)Cg(2)ii3.8437.13 (3)-3.266 (2)3.438 (2)1.72
Notes: CgCg = distance between ring centroids; Alpha = dihedral angle between planes I and J; CgI_Perp = perpendicular distance of Cg(I) on ring J; CgJ_Perp = perpendicular distance of Cg(J) on ring I; Slippage = distance between Cg(I) and perpendicular projection of Cg(J) on Ring I. Symmetry codes: (i) 1-x, -0.5+y, 0.5-z, (ii) 1-x, 0.5+y, 0.5-z.
 

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